Stable all-solid-state lithium metal batteries enabled by ultrathin LiF/Li3Sb hybrid interface layer

The PEO-LLZTO composite solid electrolyte is considered to be one of the most promising solid electrolytes. However, there is still a heavily short circuit caused by dendrite penetration due to the uneven deposition of Li on the solid electrolyte/Li anode interface. In this paper, the SbF3 is used as the precursor to treating commercial Li foils by spray painting method, and an ultrathin LiF/Li3Sb hybrid interface layer is constructed. The interface layer can improve the deposition of Li and enhance the solid electrolyte/anode interface stability effectively contributed by the high Li-ion conductivity of LiF and lithiophilic Li3Sb. Using SbF3@Li as the anode to assemble solid symmetric cells, a high current density of 0.6 mA.cm(-2) and an extended cycle life at 0.2 mA.cm(-2) for 0.2 mA.cm(-2) are obtained. Moreover, assembling full cells with the LiFePO4 or single crystal LiNi0.6Mn0.1Co0.3O2, it is found that the cycle stability and coulomb efficiency are greatly improved. The LiFePO4|PEO-LLZTO|SbF3@Li cell delivers stable cycling at 0.2 C over 200 cycles (94.5% capacity retention), and it also exhibits a superior rate capability of 127.9 mA.cm(-1) at 1 C. These results demonstrate that the modified Li anode holds large potential for all-solid-state lithium metal battery applications.